Routine centrifugation of pooled snake venoms reveals significant yields of sloughed secretory epithelia. This cell loss results from the fact that synthesis and secretion of venom on the cellular level is a very high energy absorbing process. Gennaro, J. F., Anatomical Records, vol. 136, p. 196 (1960). The secretory epithelia therefore "burn out" at a very rapid rate and require proliferative replacement at rates in excess of normal cell lines. This excess proliferation is believed to be stimulated by a snake venom growth factor (SVGF) that exists in the venom. Federation Proceedings, vol. 40:6 (1981). One of the most potent growth factors known is Epidermal Growth Factor (EGF) that stimulates the incorporation of .sup.3 [H]-thymidine into the newly synthesized DNA of human embryonic palatal mesenchymal cells by a little more than twofold. Yoneda, T. and Pratt, R. M., Science, vol. 213, pp. 563-565 (1981). Since the snake venom growth factor (SVGF mentioned above has been observed to increase the incorporation of .sup.3 [H]-thymidine into the DNA of Vero cells by elevenfold, SVGF is believed to be a more potent growth factor than EGF.